1. Field of the Disclosure
The present disclosure relates to a recording unit, and more particularly, to a recording unit which can be suitably used when a head unit with a thermal head is to be replaced.
2. Description of the Related Art
In the past, thermal transfer printers have been used which print characters or images on a recording material such as printing paper using a thermal head with heating or thermal elements formed thereon. Specifically, in the thermal transfer printers, the thermal head is brought into pressure contact with printing paper on a platen with an ink ribbon disposed between them. In the meantime, the heating or thermal elements are selectively heated in accordance with printing data, whereby ink of the ink ribbon is transferred onto the recording material; that is, thermal transfer printing is carried out.
In such thermal transfer printers, when the heating temperature of the heating or thermal elements is too high, too much of the ink of the ink ribbon is transferred onto the recording material, resulting in poor quality printing.
To solve or alleviate such a problem, in the conventional thermal transfer printers, cooling of the thermal head was carried out by forcibly radiating heat generated from the thermal head to the outside via a radiator member (for example, a thermal head attachment mount) coupled to the thermal head.
In recent years, a water-cooled cooling unit has been employed to more effectively cool down the thermal head by using cooling liquid (for example, see Patent Document 1: JP-A-6-031957). In the water-cooled cooling unit, a flow path for circulating the cooling liquid is provided in the vicinity of the thermal head, and heat transferred from the thermal head to the flow path is transformed to evaporation heat of the cooling liquid that circulates in the flow path to thereby cool down the thermal head.
Moreover, the present applicant has proposed a cooling unit configured to be detachably attached to a head unit with a thermal head in order to make it easy to replace a destroyed or fatigued thermal head with a new one (see Patent Document 2: JP-A-2006-212818). According to the cooling unit, the replacement of the thermal head can be performed in a state that the head unit is separated from the cooling unit. Unlike a cooling unit that is not separable from the head unit, it is not necessary to stop the circulation of cooling liquid and evacuate the cooling liquid in order to prevent leaking of the cooling liquid during the replacement of the thermal head. Therefore, the replacement of the thermal head becomes easy.
However, in the cooling unit (heat sink) of Patent Document 2, the attachment and detachment of the head unit is carried out by means of bolts and nuts, which requires considerable time. Therefore, a construction is desired which enables replacement of the thermal head in an easier manner.